1. Field
Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to femto base stations having network listen with self-interference cancellation.
2. Background
Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, etc. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Examples of such multiple-access networks include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA) networks.
A wireless communication network may include a number of eNodeBs that can support communication for a number of user equipments (UEs). A UE may communicate with an eNodeB via the downlink and uplink. The downlink (or forward link) refers to the communication link from the eNodeB to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the eNodeB.
In a heterogeneous wireless network operating with macro and femto base stations, femto base stations may listen for neighboring macro base station downlink signals in order to determine time and frequency synchronization. The network listen (NL) process conducted by the femto base stations may either be out-of-band, in which the NL transceiver operates in a different frequency band than the femto transceiver, or in-band, in which the NL and femto transceivers operate in the same frequency band. An in-band NL process results in substantial interference because of the RF coupling between the femto transmitter and NL receiver. To alleviate this interference, the femto transmitter may be suspended while the femto is performing the NL process through the NL transceiver. However, suspending the femto transmitter may result in degradation of quality of service for both voice and data services either through voice quality degradation or loss of data packets for data calls. Due to stringent latency requirements, this degradation may more severely impact voice quality for UEs conducting voice calls in communication with the femto base station.